A contribution to the discussion of probabilities and human hair comparisons

The paper by Gaudette and Keeping on "An Attempt at Determining Probabilities in Human Scalp Hair Comparison" in the Journal of Forensic Sciences (Vol. 19, No. 3, July 1974, pp. 599-606) has provoked considerable controversy. This paper highlights two of the sources of the controversy and shows how the probability, 1/4500, quoted by Gaudette and Keeping should be treated with caution. The necessity of the use of a likelihood ratio statistic is described. It is suggested that the hair examination form resulting from the responses to the questionnaire recently distributed by the authors and also the discussions at Quantico (Proceedings of the International Symposium on Forensic Hair Comparisons, 25-27 June 1985, Quantico VA) should be used to facilitate the collection of the data which will be necessary to enable a likelihood ratio statistic to be estimated effectively.     

Tumbling abrasions. Injuries from ricocheting bullets

Atypical entrance gunshot wounds may be produced by deflected or ricocheting bullets. One special type of atypical entrance wound involves abrasion of the skin at a site that is remote from the point of dermal penetration. These remote abrasions, termed "tumbling abrasions," are produced by bullets that tumble after impact with an intermediate target. Three cases of tumbling abrasions are presented.     

The impact of health maintenance organizations and competition on hospitals in Minneapolis/St. Paul

The Healthcare Educational and Research Foundation (HERF) in Minneapolis undertook a two-year research project to study the effects of health maintenance organizations (HMOs) and competition on the hospital industry in Minneapolis/St. Paul. This article summarizes HERF's major findings surrounding three key questions: (1) do the HMOs in Minneapolis/St. Paul use fewer hospital resources relative to conventional payers?; (2) do recent overall community trends in inpatient use suggest evidence of hospital utilization-reducing effects attributable to HMOs?; and (3) given the highly visible competitive process among Minneapolis/St. Paul providers, do hospital cost and revenue data suggest any evidence of cost-containment? The findings (based on data through 1982) indicate that for comparable patients, Twin Cities HMOs appear to use fewer medical care resources per hospitalized patient. There was, however, no clear evidence of community-wide, utilization-reducing effects directly attributable to the "competitive effect" of HMO introduction and development in the market. In addition, there was no empirical evidence that HMOs (which had enrolled 25 percent of the consumer market by 1982), or other large buyers of inpatient services, have selected hospitals on the basis of price as hypothesized by competition advocates.